"Windows is indeed slower than other operating systems in many scenarios, and the gap is worsening." That's one way to start an insider explanation of why Windows' performance isn't up to snuff. Written by someone who actually contributes code to the Windows NT kernel, the comment on Hacker News, later deleted but reposted with permission on Marc Bevand's blog, paints a very dreary picture of the state of Windows development. The root issue? Think of how Linux is developed, and you'll know the answer.

A company wanting to 'put a Linux sticker' on the box doesn't need to put a driver on a disc, they can have the driver be part of the actual kernel tree and be shipped with all Linux distros and maintained against ABI changes by the kernel devs.
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you modify and re-compile the drivers to work against the new improved ABI, and this is something the kernel devs do for you if you keep your driver in the kernel.